The invention relates to a spool for receiving a wound skein product comprising a rotationally symmetrical spool body with two axial ends provided with flange discs, said spool being divided into two parts by a substantially radial dividing surface, these parts having front surfaces running adjacent and parallel to the dividing surface, said front surfaces having locking projections on at least one surface and, on the other surface at least, detent recesses which interact with the locking projections of the other spool part respectively, interlocking therewith in the form of a bayonet catch by mutual rotation of the spool parts.
A spool of this type is disclosed in EP 404 043 A1, for example. DE 197 00 185 illustrates a similar solution.
In the case of these prior art spools, the spool parts taper conically towards the dividing surface. The advantage of the divisibility of the spools in connection with this conical tapering of the spool parts is that, once the skein product has been unwound, the spools can be taken apart and, thanks to their conical shape, stacked, so that they require little space during transport and storage.
But whilst the divisibility of the spools is associated with considerable advantages, it presents disadvantages in certain places. As, for example, when spools are used to wind very fine skein materials such as thin wires without insulation. These fine skein materials can slip into the gap between the two spool parts and become so firmly lodged that when the material is unwound, they remain in the gap and snap apart. This can hinder the process of unwinding the skein material and further necessitates additional work, as it is essential to remove any remaining skein material before reusing the spool.
Furthermore, experience has shown that it is impossible to press the two spool parts, which are usually made of plastic, so tightly together as to eliminate virtually any gap between them. This is true even where suitable sloping surfaces are provided in the bayonet connection used to join up the spool parts, or where thread-type structures are used to press the parts together (DE 40 01 250 A1).